Invasive instrument for treating vessels

ABSTRACT

It is provided an invasive instrument for the treatment of a vessel, which possibly includes secondary vessels, with a tip formed for the dissection of tissue at the distal end of a shaft to be introduced into the body. The tip includes at least one recess, in particular a vessel receptacle, which is arranged and formed such that in the operating condition of the instrument always at least one functional unit of the shaft is kept clear, so that working on the vessel, a secondary vessel and/or on the surrounding tissue is possible using or by means of the functional unit.

BACKGROUND

This invention relates to an invasive instrument for treating vesselsand to a method.

It is known to harvest the endogenous vessels used for a bypass, i.e.veins and arteries, by an invasive, frequently also minimally invasivemethod under endoscopic control. This method is called Endoscopic VesselHarvesting (EVH). In this method, especially developed instruments areemployed.

Before the actual vessel harvesting takes place, the vessel must beseparated from the tissue enclosing the vessel. First, an access iscreated by means of a small cut in direct vicinity of the vessel to beharvested, for example for harvesting the Vena saphena magna in theregion of the knee-joint gap. Subsequently, the introduction of asuitably shaped instrument and the stepwise separation (dissection) byadvancing along the vessel axis are effected under visual control and/orendoscopic view.

The known instruments can be used e.g. with an endoscope and/or acamera. From the patent specification U.S. Pat. No. 6,042,538 it isknown that an endoscope optics can be integrated into the instrument.The instrument can be formed both as disposable and as reusable product.In a reusable product, the endoscope optics also can inseparably beintegrated into the instrument.

Corresponding to the prior art, the endoscope which frequently isintegrated into the instrument is connected with a video camera, so thatthe treating physician can observe his actions on a screen.

From the patent specification U.S. Pat. No. 5,928,138 it is known that atip can be fabricated of a visually transparent material, so that duringthe dissection a good forward visibility is ensured for the operatingsurgeon via the endoscope. Such a transparent tip also is referred to asoptical dissector.

The vessel to be harvested is connected with further, smaller peripheralvessels and after dissection from the surrounding tissue must also beseparated from said vessels.

According to the prior art, this is effected by cutting devicesintegrated into the instrument. From the patent specification U.S. Pat.No. 6,022,313 it is known that such cutting device can be designed e.g.with scissors, which are advanced in a working channel of theinstrument.

From the patent specification U.S. Pat. Nos. 5,928,138 and 6,022,313 itis known that devices for guiding the vessel to be harvested can beintegrated into the instrument.

From the patent specification U.S. Pat. No. 7,645,289 it is known that atransparent tip can be shifted along the longitudinal axis of theinstrument by means of a manipulator integrated at the handle. Inaddition, it is known from the patent specification U.S. Pat. No.7,645,289 that the side of the tip facing the instrument is providedwith a cutout. The design of the cutout allows the accommodation and/orfixation of the peripheral vessels to be separated.

It is furthermore known to support the endoscopically assisted vesselharvesting by means of CO₂ gas insufflation. It is known that CO₂ gascan selectively be introduced into the body through cavities and/orchannels of an instrument for endoscopic procedures.

SUMMARY

It is the object to create an instrument for the invasive, preferablyendoscopic treatment, in particular for harvesting vessels, with whichin particular surrounding tissue can efficiently be treated in situ.

This object is solved by an invasive instrument for treating a vessel,which possibly includes secondary vessels, with a tip formed for thedissection of tissue at the distal end of a shaft to be introduced intothe body. The tip includes at least one recess, in particular a vesselreceptacle, which is arranged and formed such that in the operatingcondition of the instrument always at least one functional unit of theshaft is kept clear, so that working on the vessel, a secondary vesseland/or on the surrounding tissue is possible using or by means of thefunctional unit. By keeping clear a functional unit (e.g. a workingchannel for a cutting device), it is easier for the treating physicianto work in situ, e.g. without having to replace the tip. With aninstrument designed in this way, several functions can be carried out atthe same time, such as e.g. holding the vessel (i.e. the vesselreceptacle for the main vessel) and simultaneously working on thesecondary vessel and/or on the surrounding tissue.

Advantageously, the tip at least partly includes a conical region, aprismatic region, a region in the form of a dolphin nose, a region witha frustoconical shape and/or a region with the shape of a triangle. Withthese shapes, an efficient dissection of the surrounding tissue can beachieved.

In a further advantageous embodiment, the vessel to be treated can befixed in a spatial position with the at least one vessel receivingmeans, wherein the tip is movable relative to the shaft by means of aguide element. After introducing the invasive instrument into the body,the treating physician hence can perform e.g. a preparation of thevessel in situ.

It is also advantageous when the tip is shiftable in axial directionand/or pivotable about the longitudinal axis by up to 180°, so thatduring the procedure a vessel arranged in the at least one vesselreceiving means can be spaced selectively in particular from a cuttingdevice. By creating a rather large distance between vessel and e.g. acutting device, the risk of a damage of the vessel is minimized. Spacingcan also be expedient for other functional units, e.g. an endoscope,since a large visual range hence can be adjusted in situ.

For the handling of the tip it is advantageous when a manipulator isarranged in particular at a handle. With the same, shifting in axialdirection and/or rotating the tip can be effected selectively.

Furthermore, it is advantageous when the guide element is formedsubstantially rod-shaped and is attached at a point of the tip which islocated opposite the vessel receiving means. By a rather large spacingbetween the pivot point of the tip and the vessel receiving means it ispossible to turn the vessel receiving means far away from functionalunits in the shaft. It is also advantageous that the guide channel andthe working channel are arranged on opposite sides of the shaft.

Functional units which can be arranged in the shaft and/or in the handleof the instrument are formed at least as an endoscope channel, at leastas a working channel for receiving a cutting device, at least as a guidechannel for receiving a guide element, at least as an irrigation channeland/or at least as an insufflation channel.

It is also advantageous when the tip with the recess is designed suchthat the cutting device and/or an endoscope can be moved past the tip inan axially retracted position and/or also in an axially extendedposition.

Advantageously, the distance between extended tip and instrument tip isadjustable steplessly or in discrete steps. In this way, a particularlyefficient preparation of the vessel can be achieved.

It is advantageous when the handle and/or the shaft are designed asreusable instrument. It is also advantageous when the tip, the guide rodand/or the manipulator (13) are designed as disposable components.

For working in situ it is advantageous when at least one channel forconducting rinsing liquid and/or for sucking off undesired liquids isintegrated in the shaft.

Advantageously, the endoscope tip protrudes out of the instrument tipand into the retracted transparent tip.

In particular for cleaning purposes it is advantageous when gas, inparticular CO₂ gas for the insufflation, can be passed to the instrumenttip in an insufflation channel. It is particularly advantageous when theinsufflation channel and/or the irrigation channel are arranged relativeto the endoscope tip such that the endoscope tip can be cleaned with thegas and/or the rinsing liquid, in particular by diverting the gas streamand/or the liquid stream on the back of the tip and directing the sameto the endoscope tip.

In a further development, a video camera is arranged at the instrumenttip, wherein the video camera includes a video sensor, e.g. a CCD orCMOS sensor, along with associated electronics and suitable optics, andglass fibers, a flexible optical waveguide and/or a solid polymer rodare guided in a separate illumination channel from the handle via theshaft to the instrument tip.

For a good illumination in situ it is particularly advantageous whenLEDs are arranged at the instrument tip for illumination.

It is furthermore advantageous when the shaft at least partly has acircular or elliptical cross-section. An elliptical cross-section can beadvantageous for the arrangement of the instruments in the interior ofthe shaft. The shaft possibly can also be formed slightly flatter thanwould have been the case with a circular cross-section.

BRIEF DESCRIPTION OF THE DRAWINGS

Further embodiments are subject-matter of the sub-claims and/or will bedescribed in more detail below with reference to the Figures.

FIG. 1 shows a schematic perspective representation of an embodiment ofthe instrument for treating, in particular harvesting a vessel.

FIG. 2 shows a tip of an embodiment of the instrument.

FIG. 3 shows a sectional view through the handle of an embodiment of theinstrument.

FIG. 4 shows the use of an embodiment of the instrument.

FIG. 5 shows the tip of an embodiment with non-extended tip.

FIG. 5a shows a modified embodiment according to FIG. 5.

FIG. 6 shows the tip of an embodiment of the instrument with a tipextended axially in a distal direction.

FIG. 7 shows an embodiment with an irrigation channel.

FIG. 8 shows an embodiment with a video interface.

FIG. 9 shows an embodiment with a solid polymer rod as opticalwaveguide.

FIG. 10 shows an embodiment with LED at the tip.

FIG. 11 shows a detail of a further embodiment.

FIG. 12 shows a detail of a further embodiment concerning the flowpattern of purge gas.

FIGS. 13a, b each show sectional views through the tip and the shaft ofone embodiment.

FIG. 14 shows an exploded drawing of an embodiment of a tip with abaffle plate.

DETAILED DESCRIPTION

FIG. 1 shows the basic structure of an embodiment of an invasiveinstrument 1, in particular for harvesting vessels 14.

In the following an instrument is described, which is particularlyformed for harvesting vessels such as the Vena saphena magna (see FIG.4). In principle, the dimensions of the instrument 1 can be adapted tothe conditions of the body.

Other human vessels 14, which can be treated for example with theinstrument 1, include the Vena saphena parva (subcutaneous calf vein),the Vena cephalica brachii & antebrachii (subcutaneous vein of the upperand lower arm) or the Vena basilica (deep vein in the upper arm). Theinvention is, however, not limited to the treatment of these vessels 14.

The instrument 1 serves to invasively treat a vessel 14 (also referredto as main vessel) in the body of a human being (possibly also of ananimal) (dissection), so that it can be harvested from the body.

The instrument 1 includes a shaft 2 to be introduced into the body and ahandle 3 at the proximal end. At the distal end of the shaft 2(instrument tip 15) a tip 10 of transparent material is arranged, whoseshape and function will yet be explained below.

As shown in connection with FIG. 2, various functional units arearranged in the shaft 2. In the present example, these functional unitsinclude an endoscope channel 4 for receiving an endoscope 5 (here notshown for reasons of clarity), a working channel 6 for receiving acutting device 7 (here not shown for reasons of clarity), as well as aguide channel 8 for receiving a guide element 9 (e.g. in the form of aguide rod 9, here not shown for reasons of clarity), which serves themanipulation of the transparent tip 10. The term functional unitscomprises devices in, at and/or on the shaft 2 of the instrument 1, withwhich work and/or observations can be made in particular in the bodyand/or parts of the instrument 1 can be moved, cleaned (see e.g. FIG.12) and/or adjusted. The functional unit comprises both regions forreceiving devices (e.g. channels) and regions in which devices arearranged (e.g. cutting device 7 in cutting channel 6).

In alternative embodiments, the functional units in the shaft 2 can bearranged otherwise or also be realized in another number. For example,two or more working channels 6 can be present.

In the embodiment shown in FIG. 2, the working channel 6 and the guidechannel 8 are located away from each other as far as possible, i.e. onopposite sides of the shaft cross-section.

The transparent tip 10 substantially has a basic structure with aconical part, wherein a vessel receiving means 17 in the form of arecess (or also depression) is arranged at the circumference. The recess17, or in this case the vessel receiving means 17 with an anatomicallyshaped receptacle for the vessels 14, has a dual function which will yetbe explained in connection with FIGS. 4 and 5.

The tip 10 is formed such that a separation of tissue is possible withthe same when it is introduced into the body. In the embodiment shownhere, the tip 10 is slightly rounded, in order to avoid damages at thetissue to be separated. As will be shown later on with reference toexamples, the tip 10 also can assume other shapes.

The cross-section of the shaft 2 and the base surface of the tip 10 areformed circular in this embodiment. In principle, it is also possiblethat the shaft 2 and the tip 10 have polygonal or ellipticalcross-sections. In this case, transparent means that the tip 10 istransparent for those wavelengths at which an observation takes place.For an endoscopic observation with a usual video camera, e.g. opticallytransparent polymers (e.g. PMMA) can be used. The tip 10 is hollow frominside, so that the wall thickness of the tip 10 everywheresubstantially is the same. This is expedient, in order to ensure a bestpossible observability with an endoscope 5 through the transparent tip10.

The connecting point between guide element 9 and transparent tip 10 isnot located in the middle axis of the substantially conical body of thetransparent tip 10, but offset laterally. As can be seen in FIG. 2, theconnecting point is arranged spatially opposite the vessel receivingmeans 17 in the vicinity of the circumference of the transparent tip 10.In the position of the transparent tip 10 as shown in FIG. 2, the vesselreceiving means 17 points upwards. The tip is formed such that in thisposition it also keeps clear at least one functional unit, in this caseseveral functional units.

When the transparent tip 10 is rotated by 180° by means of the guideelement 9, the concave vessel receiving means 17 points downwards. Ascan be seen in FIG. 5, the working channel 6 also is free in thisposition, i.e. the recess 17 (i.e. the vessel receiving means) keepsclear at least one functional unit, here the working channel 6, also inthis position.

Hence it becomes clear that the vessel receiving means 17 as recess hasa dual function. On the one hand, it ensures that also in the operatingposition shown in FIG. 5 at least one functional unit is kept clear(e.g. the working channel 6). On the other hand, the recess of thevessel receiving means 17 serves as positioning means for the vessel 14(i.e. the main vessel), i.e. by rotating the tip 10 with the vesselreceiving means 17 the vessel 14 can be brought into a position in whichit can easily be treated.

In alternative embodiments, there can also be provided more than oneendoscope channel 4, more than one working channel 6 and/or more thanone guide channel 8.

In the sectional view of FIG. 3 it can be seen that at the handle 3 anopening 11 of the endoscope channel 4 for receiving the endoscope 5, anopening 12 of the working channel 6 and a manipulator 13 connected withthe guide element 9 are arranged.

In the following, the function of the design will be explained above allwith respect to FIG. 4.

When a vessel 14 is to be separated from the surrounding tissue (notshown in FIG. 4), the transparent tip 10 is arranged at the shaft 2 suchthat the base line of the tip 10 approximately corresponds to thecircumference of the shaft (see e.g. FIG. 5); the tip 10 is flush withthe shaft 2.

The transparent tip 10 here is designed such that a vessel 14 to beharvested can be picked up or held by the tip 10 such that it is keptaway from the cutting device 7, which is arranged in the working channel6, and/or is protected against inadvertent damage.

For this purpose, the transparent tip 10 (with the vessel receivingmeans 17 pointing downwards) is moved by means of the manipulator 13(see FIG. 1) via the guide element 9 away from the side of theinstrument tip 15 facing the vessel 14, along the instrument axis, i.e.the longitudinal axis of the shaft 2 (see FIGS. 2 and 4). This meansthat the transparent tip 10 is extended from proximal to distal in axialdirection.

The manipulator 13 (see FIG. 1) here acts as a kind of slidingmechanism, with which the guide element 9 and hence the transparent tip10 can be moved in the body in axial direction, and as rotary mechanism(e.g. with a wheel) with which a rotatory movement can be performed. Inprinciple, the manipulator 13 also can be distributed to severaloperating elements.

After positioning the transparent tip 10 in axial direction, thetransparent tip 10 is pivoted by means of the manipulator 13 about theaxis of the guide element 9 by up to 180°, so that the vessel 14 isarranged in the depression-like vessel receiving means 17 (see also FIG.2) and is kept away from the cutting device 7.

The cutting device 7 then can, as shown in FIG. 4, cut through e.g.secondary vessels 40, wherein the cutting device 7 can move freely inaxial direction. In FIG. 4, a scissor device is used as cutting device7. In principle, however, other cutting means are also conceivable.

In alternative embodiments, the vessel receptacle 17 can be formed asnotch or as U-shaped indentation. In any case, it is possible to disposethe vessel 14 in a vessel receptacle 17 such that it cannot easily slipout laterally.

It is possible to adjust the axial distance between the extendedtransparent tip 10 and the instrument tip 15 by means of the manipulator13 and the guide rod 9 steplessly or in discrete steps.

With the illustrated embodiment it is possible that the transparent tip10 is designed such that both in the retracted position 18 a (see FIG.5) and in the extended position 18 b (see FIG. 6) the cutting device 7can be guided past the tip 10. In FIGS. 5 and 6 it is shown that thereceiving means 17 is formed in the tip 10 such that the depression-likeformation does not cover the working channel 6.

This allows the operating surgeon to prepare vessels 14, secondaryvessels 40, and also separate the same from the surrounding tissue,during each phase of the procedure. The tip 10 is formed such that ineach phase a functional unit, here the working channel 6 with thecutting device 7 arranged therein, is operable.

The operating surgeon even can axially move the cutting device 7 furtherin distal direction beyond the tip 10, in order to cut before the actualinstrument 1 and/or the tip 10. The vessel receiving means 17 then canbe used to spatially fix the vessel 14 in a position in which anoperating surgeon can work particularly well. The rotatability of theguide element 9 allows an arbitrary positioning, wherein in each casethe necessary distance to the cutting device 7 is maintained. Due to theaxial shiftability and/or rotatability (i.e. movements relative to theshaft 2), it is also possible to align the vessel 14 with the attachedsecondary vessels 40 such that a preparation or separation of thesecondary vessel 40 is possible.

This allows in particular the vessel harvesting without change of theinstrument and/or removal of the transparent tip 10.

FIG. 5a shows a modification of an embodiment which is shown in FIG. 5,in a slightly different perspective. The vessel receptacle 17 here isturned downwards, so that the functional unit, in this case the workingchannel 6, is exposed in axial direction through the recess of thevessel receptacle 17. Thus, the tip 10 with the recess 17 cannot only beused for holding or placing vessels 14, but due to the recess 17 the tip10 also is designed such that the functional units are exposed.

In a further exemplary embodiment of the instrument 1, the componentshandle 3 and/or shaft 2 are designed as reusable instrument. The sameare shaped such that they can be prepared mechanically and subsequentlybe sterilized with commonly used sterilization methods, in particularthe steam sterilization. The tip 10, the guide element 9 and/or themanipulator 13 can be designed as disposable components and due to theirmodular construction can easily be mounted in the reusable instrumentand again be removed from the same.

In a further embodiment (see FIG. 7), an irrigation channel 20 forsupplying and sucking off rinsing and body fluids is arranged in theshaft 2, so that a tip 19 of the endoscope 5 and the transparent tip 10can be cleaned in situ by means of an irrigation. The effect of cleaningis intensified when—as shown in FIG. 12—the endoscope tip 19 protrudesout of the instrument tip 15 and into the retracted transparent tip 10.The irrigation channel 20 ends in the handle in a port 21 for supplyingand sucking off rinsing and body fluids (see FIG. 1).

A further exemplary embodiment (see FIG. 12) allows that CO₂ gas (oralso another gas) for the insufflation is passed to the instrument tip15 in an integrated insufflation channel 22 as functional unit. Theposition of the insufflation channel 22 relative to the endoscope tip 19is to be arranged such that with the CO₂ gas the endoscope tip can beliberated from undesired liquid. By way of example, this can be realizedin that the CO₂ gas stream is diverted on the back of the transparenttip 10 and directed to the endoscope tip 19. The channel 22 ends in thehandle in a port 23 (see FIG. 1). FIG. 12 also shows a rinsing functionwith which a rinsing liquid is sprayed from an irrigation channel 20. Inthe side view of FIG. 12, irrigation channel 20 and insufflation channel22 can only be seen laterally at the exit of the jets. In a furtherexemplary embodiment, the instrument 1 is designed as disposableinstrument, wherein the instrument 1 in principle can have the sameshape and function as described above. For this purpose, the componentshandle 3 and shaft 2 are designed as disposable components. In thisexemplary embodiment, the tip 10, the guide element 9 and/or themanipulator 13 consequently are firm, inseparable components of thedisposable instrument. Into the disposable instrument there can also beintegrated an insufflation channel 22 for the insufflation and a workingchannel 20 for the irrigation and/or aspiration.

In a further exemplary embodiment (FIG. 8), the endoscope 5 can bereplaced by a video camera 27 integrated at the instrument tip 15 or canbe used together with the same. This video camera can include a videosensor, e.g. CCD or CMOS sensor, along with associated electronics andsuitable optics. In the exemplary embodiment described here, the glassfibers 28 usually integrated in the endoscope 5, which serve thetransmission of light for illuminating the operating field, are guidedin a separate illumination channel 29 from the handle 3 via the shaft 2to the instrument tip 15.

In a further embodiment (FIG. 10), the glass fibers 28 in the disposableinstrument are replaced by a solid polymer rod 30. The same can bedesigned in an arbitrary, space-saving shape which is suitable forconducting light. Alternatively or also in addition, a flexible opticalwaveguide of silicone or another suitable material can be used.

In a further exemplary embodiment, the glass fibers 28 in the disposableinstrument are replaced by LEDs 31 positioned at the instrument tip 15.In principle, combination possibilities are also conceivable.

The same can be designed in an arbitrary, space-saving shape which issuitable for illuminating the field of view of the video camera 27.

FIGS. 13a, b show sectional views through a transparent tip 10 and ashaft 2, wherein here an endoscope 5 is shown as functional unit. InFIG. 13a , the transparent tip 10 is shown in the distal position. In acutout 24 a few water droplets are shown, which are left on the insideof the tip 10 e.g. after the irrigation. The cutout 24 can be part of abaffle plate which is arranged at the proximal end of the tip 10. Afurther embodiment of this proximal baffle plate is shown in FIG. 14.

When the tip 10 now is brought into the proximal position (FIG. 13b ),the tip of the endoscope 5 protrudes into the cutout 24. The protrudingend of the endoscope 5 compresses the water droplets in the cutout 24,so that a substantially uniform film is obtained in the gap between thecutout 24 and the endoscope 5. This does not impair the opticalproperties. Furthermore, it can be seen in FIGS. 13a, b that theinterior of the tip is formed substantially hollow, above all in theregion which is located axially in the field of view of the endoscope 5.

In FIG. 14, a tip 10 is shown in the form of an exploded drawing, whichis formed as free form. The diameter tapers from proximal to distal. Therecess 17 points downwards. The interior of the tip 10 here is formedsubstantially hollow, wherein the wall thicknesses of the transparentmaterial are substantially the same.

At the proximal end of the transparent tip 10 a baffle plate 25 isarranged, at which e.g. rinsing liquid can be diverted according to theprocedure in FIG. 12, in order to selectively clean an endoscope 5. Tosupport this cleaning, the baffle plate 25 includes at least onediverting means 26 with which the irrigation jet can selectively bedirected to the endoscope 5. The diverting means 26 here is formed asdepression. In principle, other forms which e.g. protrude beyond thebase surface of the baffle plate 25 can also be used. Alternatively orin addition, other functional units such as e.g. the cutting device 6also can be cleaned by the irrigation jet.

LIST OF REFERENCE NUMERALS

-   1 instrument-   2 shaft-   3 handle-   4 endoscope channel-   5 endoscope-   6 working channel-   7 cutting device-   8 guide channel-   9 guiding device-   10 transparent tip-   11 opening of the endoscope channel-   12 opening of the working channel-   13 manipulator of the guiding device-   14 vessel-   15 instrument tip-   16 instrument axis-   17 vessel receiving means-   18 a retracted position of the tip-   18 b extended position of the tip-   19 endoscope tip-   20 irrigation channel-   21 port of irrigation channel-   22 insufflation channel-   23 port of gas channel-   24 cutout-   25 baffle plate-   26 diverting means-   27 video camera-   28 glass fibers-   29 illumination channel-   30 solid polymer rod-   31 LED-   40 secondary vessel

1. An invasive instrument for treating a vessel, which possibly includessecondary vessels, comprising: an elongated shaft extending along alongitudinal axis and having a proximal end and a distal end to beintroduced into a body of a subject, the distal end having a workingopening of a working channel that is located in the elongated shaft; adissection tip coupled to a guide element that is operably coupled tothe shaft so that the dissection tip has a retracted tip positionproximal to the distal end of the shaft and a shifted tip positionspaced apart from the distal end of the shaft that is shifted relativeto the retracted position, wherein the dissection tip is formed for thedissection of tissue, wherein the dissection tip includes at least onevessel receptacle in the form of an anatomically shaped recess extendingsubstantially along the longitudinal axis of the elongated shaft; atleast one functional unit operably coupled with the shaft so as to havea retracted functional position within the working channel of the shaftwhen the dissection tip is in the retracted tip position and have adissection functional position when the at least one functional unit isextended from the distal end of the shaft when the dissection tip is inthe shifted tip position such that the at least one vessel receptacle isspaced apart from the at least one functional unit.
 2. The invasiveinstrument according to claim 1, wherein the dissection tip at leastpartly includes a conical region, a prismatic region, a region in theform of a dolphin nose, a region with a frustoconical shape and/or aregion with the shape of a triangle.
 3. The invasive instrumentaccording to claim 1, wherein the dissection tip is shiftable in axialdirection and/or pivotable about the longitudinal axis by up to 180°, sothat during the procedure a vessel arranged in the at least one vesselreceptacle can be spaced selectively in particular from a cutting deviceof the functional unit.
 4. The invasive instrument according to claim 1,further comprising a handle at the proximal end of the shaft, and amanipulator, in particular arranged at the handle, for axially shiftingand/or rotating the dissection tip relative to the distal end of theshaft between the retracted tip position and the shifted tip position.5. The invasive instrument according to claim 1, wherein the guideelement is formed substantially rod-shaped and is attached at a point ofthe dissection tip which is located opposite the vessel receptacle. 6.The invasive instrument according to claim 1, wherein a guide channelhaving the guide element and the working channel having the at least onefunctional unit are arranged on opposite sides of the shaft.
 7. Theinvasive instrument according to claim 1, wherein in the shaft and/or inthe handle of the instrument at least one endoscope channel, at leastone working channel for receiving a cutting device, at least one guidechannel for receiving a guide element, at least one irrigation channeland/or at least one insufflation channel are arranged.
 8. The invasiveinstrument according to claim 1, wherein the dissection tip with therecess is designed such that the cutting device and/or an endoscope canbe moved past the dissection tip in an axially retracted position and/oralso in an axially extended position.
 9. The invasive instrumentaccording to claim 1, wherein the distance between extended dissectiontip and instrument tip is adjustable steplessly or in discrete steps.10. The invasive instrument according to claim 1, wherein the handleand/or the shaft are designed as reusable instrument.
 11. The invasiveinstrument according to claim 1, wherein the dissection tip, the guideelement and/or the manipulator are designed as disposable components.12. The invasive instrument according to claim 1, further comprising atleast one channel integrated into the shaft for conducting rinsingliquid and/or for sucking off undesired liquids.
 13. The invasiveinstrument according to claim 1, wherein an endoscope tip operablycoupled with the shaft protrudes out of the instrument tip and into theretracted transparent tip.
 14. The invasive instrument according toclaim 1, further comprising an insufflation channel such that a gas, inparticular CO₂ gas, for the insufflation can be passed to the instrumenttip in the insufflation channel.
 15. The invasive instrument accordingto claim 1, wherein the insufflation channel is arranged relative to theendoscope tip such that the endoscope tip can be cleaned with the gas,in particular in that the gas stream is diverted on the back of thedissection tip and directed to the endoscope tip.
 16. The invasiveinstrument according to claim 1, wherein at the instrument tip a videocamera is arranged, wherein the video camera includes a video sensor,e.g. a CCD or CMOS sensor, along with associated electronics andsuitable optics, and glass fibers, a flexible optical waveguide and/or asolid polymer rod are guided in a separate illumination channel from thehandle via the shaft to the instrument tip.
 17. The invasive instrumentaccording to claim 1, wherein at the instrument tip at least one LED isarranged for illumination.
 18. The invasive instrument according toclaim 1, wherein the dissection tip includes at least one diverter foran irrigation jet.
 19. The invasive instrument according to claim 1,wherein the shaft has an at least partly circular or ellipticalcross-section.
 20. The invasive instrument according to claim 1, whereinwhen in the retracted tip position the at least one vessel receptacle ofthe dissection tip is aligned with the working channel so that the atleast one functional unit is movable relative to the dissection tip whenthe at least one functional unit is moved between an axially retractedposition and an axially extended position.
 21. The invasive instrumentaccording to claim 1, wherein when in the retracted tip position theendoscope is aligned with the working channel so that the endoscope ismovable relative to the dissection tip when the endoscope is movedbetween an axially retracted position and an axially extended position.22. A surgical method performed with an invasive instrument, wherein a)forming a cut into the skin of a body, b) introducing a dissection tipof the invasive instrument into the cut along a vessel, in order toseparate surrounding tissue from the vessel, c) during introductionand/or in the end position of the dissection tip treating thesurrounding tissue, a secondary vessel and/or a vessel with a functionalunit through a recess at the dissection tip, without separating theconnection of the dissection tip from the instrument.
 23. The surgicalmethod according to claim 22, wherein after being introduced through thecut, at least one functional unit is at least partly cleaned by a gasand/or a rinsing liquid.